$(70+22i)-(71+70i)=$ Express your answer in the form $(a+bi)$.
Background Complex numbers can be added or subtracted by separately adding or subtracting their real and imaginary terms. To add or subtract complex numbers: Expand parentheses (attending to minus signs outside of parentheses if necessary) Combine all real terms (terms that do not contain $i$ ), and add or subtract them. Combine all imaginary terms (terms that contain $i$ ), and add or subtract them. Combining Like Terms $\begin{aligned} ({70}+{22}i)-({71}+{70}i)&={70}+{22}i-{71}-{70}i \\\\ &={70}-{71}+{22}i-{70}i \\\\ &={-1}{-48}i \end{aligned}$ Summary $({70}+{22}i)-({71}+{70}i)={-1}{-48}i$